10 documents found, page 1 of 1
White on blue: A study on underglaze-decorated ceramic tiles from 15th-16th-cen...
Coentro, S.; Alves, L.C.; Coll Conesa, J.; Ferreira, T.; Mirão, J.; Silva, R.C.; Trindade, R.; Muralha, V.S.F.This study characterises and compares tin-opacified underglaze-decorated tiles from Valencian and Sevillian provenances. This technique, where the cobalt and manganese pigments are applied below an opaque white glaze, was used in the Iberian Peninsula between the 14th and early 16th centuries. The chemical and morphological characterisation of the glazes was performed by Optical Microscopy (OM), Scanning Electr...
Glaze Technology in Hispano-Moresque Ceramic Tiles: A Comparison Between Portug...
Coentro, S.; Alves, L.C.; Relvas, C.; Ferreira, T.; Mirão, J.; Molera, J.; Pradell, T.; da Silva, R.C.; Muralha, V.S.F.For the first time, Hispano-Moresque glazed tiles from Portuguese and Spanish collections were studied together and compared. This work is included in a wider study tackling the technology of Hispano-Moresque tile production from several collections in the Iberian Peninsula. While showing many similarities, differences were identified between collections, regarding both chemical and morphological characteristic...
Tin determination in fistula seals from Conimbriga and Augusta Emerita
Gomes, S.S.; Valério, P.; Alves, L.C.; Araújo, M.F.; Monge Soares, A.M.; Correia, Virgílio Hipólito
Amastigota forms resembling Leishmania sp. on corneal ulceration in a dog: case...
Brito, F.L.C.; Alves, L.C.; Maia, F.C.L.; Albuquerque, A.R.; Ortiz, J.P.D. [UNESP]; Laus, J.L. [UNESP]Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:55:49Z No. of bitstreams: 1 S0102-09352007000100014.pdf: 193517 bytes, checksum: f33893658be903b8119539de08ecb38e (MD5); Made available in DSpace on 2013-08-22T18:55:49Z (GMT). No. of bitstreams: 1 S0102-09352007000100014.pdf: 193517 bytes, checksum: f33893658be903b8119539de08ecb38e (MD5) Previous issue date: 2007-02-01; Made availabl...
Towards the understanding of the intentionally induced yellow luminescence in G...
Rodrigues, J; Miranda, S.M.C; Fernandes, A.J.S; Nogales, E; Alves, L.C.; Alves, E.; Tourbot, G; Auzelle, T.; Daudin, B.; Méndez, B.; Trindade, T.Gallium nitride (GaN) has gained a lot of attention due to its high range of applications as solid state light emitters and detectors. However, the nitride samples often evidence deep level optically active defects affecting their performance on the high energy spectral region. This is the case for the commonly observed yellow luminescence (YL) band detected in bulk samples and thin films. Despite the large amo...
AIN content influence on the properties of Al x Ga1- x N doped with Pr ions
Fialho, M.; Magalhães, Sérgio; Alves, L.C.; Marques, C.; Maalej, R.; Monteiro, Teresa; Lorenz, K.; Alves, E.The purpose of this work is the study of the structural and optical properties of Alx Ga1- x N films grown on (0 0 0 1) sapphire substrates with different AlN molar fraction implanted with 150 keV of praseodymium ions with a fluence of 2.5 × 1014 cm-2. The main goal is to achieve the optical doping of Alx Ga1- x N with the rare earth Pr. Structural properties, damage accumulation and Pr lattice site location we...
Damage recovery and optical activity in europium implanted wide gap oxides
Alves, E.; Marques, C.; Franco, N.; Alves, L.C.; Peres, M.; Soares, M.J.; Monteiro, T.In this study we compare and discuss the defects and optical behaviour of sapphire and magnesium oxide single crystals implanted at room temperature with different fluences (1 × 1015-1 × 1016 cm -2) of europium ions. Rutherford backscattering channelling shows that for fluences above 5 × 1015 cm-2 the surface disorder level in the Al-sublattice reaches the random level. Implantation damage recovers fast for ann...
Structural and optical properties of Zn0.9 Mn0.1 O/ZnO core-shell nanowires des...
Kaydashev, V.E.; Kaidashev, E.M.; Peres, M.; Monteiro, T.; Correia, M.R.; Sobolev, N.A.; Alves, L.C.; Franco, N.; Alves, E.Core-shell ZnO/ZnMnO nanowires on a-Al2O3 and GaN (buffer layer)/Si (111) substrates were fabricated by pulsed laser deposition using a Au catalyst. Two ZnO targets with a Mn content of 10% were sintered at 1150 and 550 °C in order to achieve the domination in them of paramagnetic MnO2 and ferromagnetic Mn2O3 phases, respectively. Cluster mechanism of laser ablation as a source of possible incorporation of seco...
Structural and optical properties of Er3+ ion in sol-gel grown LiNbO3
Graça, M.P.F.; Valente, M.A.; Peres, M.; Cruz, A.; Soares, M.J.; Neves, A.J.; Monteiro, T.; Alves, L.C.; Alves, E.Er-doped lithium niobate (LiNbO3) ceramics embedded in silica were grown by the sol–gel method. The dried gel 91SiO2–4Li2O–4Nb2O5–Er2O3 (mol%) was subsequently heat treated between 500 and 750 °C. X-ray diffraction and Raman spectroscopy have detected the crystallization of LiNbO3 and ErNbO4 in samples treated at temperatures above 600 °C. At least two Er-related optical centres have been identified by low-temp...
Luminescence studies of Co implanted sapphires
Monteiro, T.; Soares, M.J.; Santos, L.; Boemare, C.; Cascalheira, J.; Alves, L.C.; Alves, E.Sapphire single crystals implanted with different fluences of cobalt and subjected to annealing treatments in vacuum and in air during 1 h at 1000 degreesC were studied by optical and structural techniques. At room temperature the absorption mainly occurs in the ultraviolet (UV) being the luminescence dominated by a UV/blue broad emission band and a highly structured red emission. Structural analysis indicates ...